This theme includes a nice animated progress bar. It was tested on openSUSE 12.1. Theme supports only 1024x768. If you take it for difference resolution you must change the config file and the images resolution. Hope you like it :)
-=Installation=-
Before you'll install this theme, I recommend...

Based on Cristian Rodriguez's SuSE Elegant theme, but supports many more resolutions. Also has small improvements to the graphics.
Get the matching KDM and KSplash themes for a consistent UI.
You can find the original SuSE Elegant theme at...

Slackware bootsplash screen based on the good one from johngreenwood.
source picture: http://nategreene.wordpress.com/2008/11/19/digital-blasphemy/
Unpack in /etc/bootsplash/themes
You'll need also the file bootsplash-3.1 and a kernel patch
Use therefore the second link to the Slackware wiki
For...

A new bootsplash for Slackware.
The progress-bar is the line under the slackware logo...
Picture from digitalblasphemy.com
Unpack in /etc/bootsplash/themes
For the info, please see the extra link,
If you need the newest kernel patch, use the extra download link